Buoyant Force Math Problems: Calculating Densities of Metal and Unknown Liquid

AI Thread Summary
To determine the densities of the metal and the unknown liquid, the weights of the metal in air, water, and the unknown liquid are used to apply the principle of buoyancy. The metal weighs 50 N in air, 36 N in water, and 41 N in the unknown liquid, allowing for calculations based on the buoyant force experienced in each medium. The density of the metal can be calculated using the formula d = m/v, where the mass is derived from the weight and gravitational acceleration. The discussion highlights that temperature and pressure can affect density, particularly for liquids, but the relevance of temperature changes in this specific problem is debated. Ultimately, accurate density calculations require careful consideration of buoyancy and the properties of the substances involved.
WhiteTiger09
Messages
1
Reaction score
0
A piece of metal weighs 50 N. in air, 36.0 N in water, and 41.0 in an unknown liquid. Find the densities of the following:
The metal
The unknown liquid
 
Physics news on Phys.org
What have you tried so far?
 
WhiteTiger09 said:
A piece of metal weighs 50 N. in air, 36.0 N in water, and 41.0 in an unknown liquid. Find the densities of the following:
The metal
The unknown liquid

----
d=m/v. • Density of a substance is affected by temperature and pressure. These vary according to the physical properties of the substance. The effect of temperature on the density of solids and gases varies widely. Gases are most affected; solids are least and liquids ranging generally in between.
 
miragab said:
----
d=m/v. • Density of a substance is affected by temperature and pressure. These vary according to the physical properties of the substance. The effect of temperature on the density of solids and gases varies widely. Gases are most affected; solids are least and liquids ranging generally in between.

I don't think temperature is relevant in that problem
 
If the temperature of the liquid changes, the S.G. may also change. Because temperature change will cause the liquid to expand or contract, depending on whether the temperature goes below or above the standard temperature.
The S.G. or Mass Density of most liquid is calculated at a Standard Temperature (60°F).

(The Effect of Temperature is that, as the temperature of the liquid increases, the liquid expands and gets lighter per volume. Consequently, the force per unit area will decrease. On the other hand, as the temperature of the liquid decreases, the liquid contracts and becomes heavier per volume and causes the force per unit area to increase.)---
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top